The genus Cinnamomum

Anti-inflammatory action
Pharmacology and Toxicology of Cinnamon and Cassia 261
Kirthikar and Basu (1975) and Ambasto (1986) have reported the anti-inflammatory
action of cinnamon. It relieves pulmonary inflammation (Asolkar et al., 1986;
Agarwall, 1997; Warrier et al., 1994). The Japanese plant Cinnamomum seiboldii has
shown to possess anti-inflammatory action, which has been attributed to a series of
tannins (Newall et al., 1996). A study conducted on mice with 70% ethanolic extract
of cinnamon gave promising results on acute inflammations (Kubo et al., 1996).
The extract inhibited the increase in vascular permeability induced by acetic acid.
It inhibited the paw oedema induced by carragenan as well as seratonin, whereas it was
ineffective against bradykinin and histamine-produced inflammations. Little effect was
shown on secondary lesions in the development of adjuvant induced arthritis. It is also
useful in pulmonary inflammations. A herbal ophthalmic medicament called
Ophthacare, which contains 0.5% cinnamon, was tested for its anti-inflammatory activity
on ocular inflammations in rabbit and found to be effective (Mitra et al., 2000).
Action on the cardio-vascular system
The ‘Indian Materia Medica’ (Nadkarni, 1976) and the ‘Indian Medicinal Plants – A
Compendium of 500 species’ (Warrier et al., 1994) consider cinnamon as a herbal drug
which has cardiovascular effects. A decoction of the herb increases coronary flow in
guinea pig heart and antagonised pituitrin-induced reduction of flow. An oral dose of
1.2 g/kg of the decoction for six days improved pituitrin-induced acute myocardial
ischemia. Intra-arterial injection of the decotion did not affect blood pressure but
markedly decreased peripheral vascular resistance, suggesting a direct vasodilatation of
peripheral vessels (Wang, 1983). In another study using anesthetised dogs and guinea
pigs cinnamaldehyde produced a hypotensive effect mainly due to vasodilatation. An
increase in cardiac contractile force and beating rate was exerted by cinnamaldehyde
(Harada and Yano, 1975). Cinnamaldehyde induced the release of catacholamines from
the adrenal glands of dogs. The positive inotropic and chronotropic effects (adrenergic
impulses with an increase in rate and force of contraction) of cinnamaldehyde on
perfused isolated guinea pig heart were presumably due to the release of endogenous
catecholamines (Harada and Saito, 1978). Circulatory stimulant effects of cinnamon
have been reported in several books on medicinal plants and also in Ayurveda
(Bhattacharjee, 1998; Asolkar et al., 1986). Tanikawa et al. (1999) observed that aqueous
extract of the bark relaxed rat aorta ring (precontracted with PGF 2) preparation
with intact epithelium. Tannins do not relax specimens without epithelium. They
attributed the vasodialatory action to the tannins. It has also been observed that with
increasing molecular weight of tannins the intensity of relaxation also increases.
Inhibition of platelet aggregation and thrombosis has been reported by Matsuda et al.
(1987). A 70% methanol extract of C. cassia bark has shown significant inhibition of
intravascular coagulation in rats. Cinnamaldehyde exerts a similar action.
Hypoglycemic activity
Cinnamon is considered to be a herbal remedy for diabetes. Ayurveda texts and folk
medicinal uses support this claim. Studies conducted on rabbit using an aqueous
extract established the hypoglycemic effect (Asolkar et al., 1986). It is reported in many